Hearing Restored: One Shot Reverses Deafness in Weeks

Groundbreaking Gene Therapy Restores Hearing in Deaf Children and Adults

A pioneering gene therapy has enabled a seven-year-old girl to regain her hearing and converse fluently with her mother just four months after receiving treatment — a milestone that marks a major leap forward in the fight against genetic deafness.

The breakthrough, led by Otovia Therapeutics in collaboration with Karolinska Institutet and several hospitals in China, delivered promising results across a small group of participants. The therapy centers on a single injection of a modified virus carrying a healthy copy of the OTOF gene — the gene responsible for producing otoferlin, a crucial protein that allows the ear to translate sound into brain signals.

“This represents a major advance in the genetic treatment of hearing loss,” said Dr. Maoli Duan, a co-author of the study and consultant at Karolinska Institutet. “And we’re only scratching the surface.”

The clinical trial involved ten patients, aged 1 to 24, all diagnosed with hearing loss stemming from mutations in the OTOF gene. The therapy was administered by injecting an engineered adeno-associated virus (AAV) into the cochlea via the round window membrane — a delicate structure at the base of the inner ear.

Most patients began experiencing partial hearing restoration within one month of the injection. By the six-month mark, every participant had shown substantial improvement. On average, the threshold of detectable sound dropped from 106 decibels — equivalent to the volume of a chainsaw — to just 52 decibels, similar to a quiet conversation.

Younger children responded particularly well. Those aged five to eight showed the most rapid and significant hearing gains. Among them was the seven-year-old girl whose recovery became a centerpiece of the study, demonstrating the profound potential of early intervention.

Importantly, the therapy also yielded benefits in older participants, suggesting broad applicability beyond childhood. Researchers believe this could signal the beginning of a new era in treating genetic hearing impairments — one where a single targeted procedure could transform lives.

While earlier, smaller trials in China had already shown encouraging results in children, this marks the first time the gene therapy has been extended to include both teenagers and adults. “Many participants experienced significant improvements in hearing, which could dramatically enhance their quality of life,” noted Dr. Maoli Duan. “Our next step is to closely monitor these individuals to determine how long the benefits will last.”

The study also confirmed that the treatment was safe and generally well-tolerated. The most frequently observed side effect was a temporary drop in neutrophils—a type of white blood cell—but no serious complications were recorded during the 6 to 12-month follow-up.

“This is just the beginning for OTOF,” said Dr. Duan. “Our research—and that of others—is already expanding to target more prevalent genetic causes of hearing loss, such as GJB2 and TMC1. These genes are more complex to treat, but preliminary results from animal studies are promising. We believe that, in time, gene therapy will offer hope to a broader group of patients affected by different types of genetic deafness.”

The project was carried out in partnership with several institutions, including Zhongda Hospital at Southeast University in China. Funding came from Chinese scientific programs and Otovia Therapeutics Inc., the biotech company that developed the therapy and employs many of the study’s contributing scientists.

The gene therapy was found to be safe, with no major side effects reported. The most frequent issue observed was a short-term decrease in neutrophils, a type of white blood cell. However, none of the participants experienced any significant health complications during the 6 to 12-month monitoring period.